The FAQ mentions this:
What happens to my Games with Gold games if I cancel my Xbox Live Gold or Xbox Game Pass Ultimate subscription?
On Xbox One, you’ll no longer be able to access your Games with Gold titles if you cancel your subscription. However, if you decide to renew your subscription at any time, you’ll be able to access and play your previously redeemed Games with Gold titles again.
On Xbox 360, any Games with Gold titles that you redeem as an Xbox Live Gold or Xbox Game Pass Ultimate member are yours to keep, regardless of whether you continue your subscription.
So if I understood it correctly I will only be able to play 360 games on a 360 because when my subscription ends ALL of "games with gold" games are not accesible from an Xbox One.
Does it work that way or are the 360 "games with gold" available on both consoles no matter what the subscription status is?